Conversion des signaux Radiofréquences par un mélangeur tout-optique à base d'un SOA

National audienceThe frequency conversion of RF signals by optical means is a phenomenon which attracts the attention in transmitting information over radio frequencies. In this work we present All-optical mixer based on cross gain modulation in a SOA (Semiconductor Optical Amplifier)

SIMULATION ET MESURE D'UN SYSTÈME DE TRANSMISSION CO-OFDM EMPLOYANT DES AMPLIFICATEURS OPTIQUES À SEMI-CONDUCTEURS

National audienceIn this paper, a numerical model of semiconductor optical amplifiers (SOA) is experimentally validated in terms of non-linearity of the SOA, particularly the phase-amplitude coupling factor and four-wave mixing (FWM). This model was then used in a simulation platform of coherent optical OFDM system (CO-OFDM) in the presence of a signal amplified by an SOA having an effective data rate of 10.94 Gb/s. The EVM (Error Vector Magnitude) values obtained by the simulation were validated experimentally for a wide range of powers and wavelengths

Influence des amplificateurs optiques à semi-conducteurs (SOA) sur la transmission cohérente de signaux optiques à format de modulation multi-porteuses (CO-OFDM)

Le futur système de transmission multicanaux (WDM) pourrait mettre à profit l'utilisation d'amplificateurs optiques à semi-conducteurs (SOA), pour bénéficier notamment de leur grande bande passante optique pour l'amplification du signal. Dans ce travail, nous étudions l influence des SOA sur la transmission cohérente de signaux OFDM optiques (CO OFDM). Cette technique, récemment proposée, permet à la fois d augmenter l'efficacité spectrale de la transmission et de compenser les imperfections linéaires du canal optique. Nous avons développé, dans ce travail, une chaîne expérimentale de transmission de signaux à formats de modulation complexes tout-optiques et une plateforme de simulation au niveau système. Les résultats obtenus par simulation, au niveau composant et au niveau système, sont en très bon accord avec ceux obtenus par les mesures expérimentales à la fois pour des formats de modulation QPSK et QPSK CO-OFDM. À travers différentes mesures et simulations, l étude a permis de cerner clairement l influence des paramètres du SOA sur la qualité de transmission des données. Les non-linéarités induites par le SOA, telles que le couplage phase amplitude, l auto modulation du gain et de la phase (SGM et SPM), la modulation croisée du gain et de la phase (XGM et XPM) et le mélange à quatre ondes (FWM), jouent de façon importante sur les performances de ce format de modulation multi-porteuses ; leur influence a donc été analysée avec précision. Les connaissances acquises permettront à l avenir d une part de mieux définir les conditions d utilisation des SOA dans les réseaux de transmission et d autre part aideront à l optimisation de nouvelles structures de SOA conçues pour la transmission de données à très haut débit utilisant des formats de modulation complexes.Future wavelength division multiplexing (WDM) systems might take advantage from the use of semiconductor optical amplifiers (SOA), especially to benefit from their large optical bandwidth for signal amplification. In this work, we study the influence of SOAs on the coherent optical-OFDM (CO OFDM) transmission system. This recently proposed technique allows both to increase the spectral efficiency of the transmission and to compensate the linear imperfections of the optical channel. In this work, we have developed an experimental setup for signal transmission operating with advanced optical modulation formats and a system level simulation platform. Simulation results, both at the component level and at the system level, are in very good agreement with those obtained from experimental measurements in the case of both QPSK and QPSK CO-OFDM signals. The study has clearly identified, through various measurements and simulations, the influence of SOA parameters on the quality of data transmission. Nonlinearities induced by the SOA, such as phase-amplitude coupling, self gain and phase modulation (SGM and SPM), cross gain and phase modulation (XGM and XPM) and the four-wave mixing (FWM) affect the performances of this multicarrier modulation format. Their influence is studied very precisely in this work. This acquired knowledge will allow, on the one hand, better defining the conditions of use of SOAs in the transmission networks and, on the other hand, helping to optimize new structures of SOA designed for very high bit rate data transmissions using complex modulation formats.BREST-SCD-Bib. electronique (290199901) / SudocSudocFranceF

Performance improvement of a SOA-based coherent optical-OFDM transmission system via nonlinear companding transforms

International audienceCoherent-Optical OFDM systems are known to be sensitive to large peak-to-average power ratio (PAPR) at the transmitter output, due to nonlinear properties of some components involved in the transmission link. In this paper, we investigate the impact of an amplification of such signals via a semiconductor optical amplifier (SOA), considering some recent experimental results. An efficient tradeoff between BER performance, computational complexity and power efficiency is performed by a proper design of Wang's nonlinear companding function, considered for the first time in an optical communication context. A BER advantage of around 3 dB can hence be obtained over a standard system implementation not using PAPR reduction. The designed function also proves to be more efficient than µ-law function, considered in the literature as an efficient companding scheme

ANALYSE THÉORIQUE DE L'INFLUENCE DES SOA EN PRÉSENCE DE SIGNAUX OPTIQUES OFDM DANS LES SYSTÈMES DE TRANSMISSION A RÉCEPTION COHÉRENTE

National audienceIn this work, we study theoretically and by simulation the influence of SOA's nonlinearities on the amplification of optical signals in the context of OFDM transmission systems with coherent reception. We present the co-simulation environment developed for this study, for both transmission and reception. This platform also enables to study the amplification of several complex optical modulation formats of the optical carrier

SIMULATION D'UNE CHAÎNE DE TRANSMISSION DE SIGNAUX OPTIQUES OFDM AMPLIFIÉS PAR DES SOA POUR DES SYSTÈMES À RÉCEPTION COHÉRENTE

International audienceIn this paper, we present a co-simulation technique to analyze the influence of the SOA's nonlinearities on the amplification of optical OFDM signals in the transmission systems with coherent reception. This simulation platform also enables to study the amplification of several complex optical modulation formats of the optical carrier

PERFORMANCES DES SOA SUR UNE LARGE BANDE PASSANTE OPTIQUE DANS UN SYSTÈME DE TRANSMISSION OPTIQUE CO-OFDM

National audienceIn this paper, we present a study of the influence of semiconductor optical amplifiers (SOAs) on an optical transmission system CO-OFDM. This study is conducted by simulation over a wide optical bandwidth. We evaluate the signal quality through its error vector magnitude (EVM: Error Vector Magnitude), taking into account the main parameters of the SOA - as the phase-amplitude coupling factor, the saturation power and noise factor - which influence the non-linear effects and especially the four-wave mixing (FWM four wave mixing)

A Joint Linearization/Companding Approach for Improving a CO-OFDM Transmitter

International audience—The joint use of peak-to-average power ratio (PAPR) reduction and linearization via digital predistortion is investigated in this letter, with the view to improve the performances of coherent optical OFDM (CO-OFDM) systems employing a semiconductor optical amplifier (SOA). PAPR reduction is performed via Wang's nonlinear companding transform (WNCT), which has been recently pointed out as a pertinent choice for optical communications, and a Filter Lookup Table (FLUT) scheme is considered for linearizing the transmitter. Experimental results prove the effectiveness of the proposed scheme, as a lower EVM is achieved with respect to system implementations using only PAPR reduction or linearization

The EPOC project: Energy Proportional and Opportunistic Computing system

15397International audienceWith the emergence of the Future Internet and the dawning of new IT models such as cloud computing, the usage of data centers (DC), and consequently their power consumption, increase dramatically. Besides the ecological impact, the energy consumption is a predominant criteria for DC providers since it determines the daily cost of their infrastructure. As a consequence, power management becomes one of the main challenges for DC infrastructures and more generally for large-scale distributed systems. In this paper, we present the EPOC project which focuses on optimizing the energy consumption of mono-site DCs connected to the regular electrical grid and to renewable energy sources